The cytokine IL-4 is well studied for its role in driving allergic/asthmatic CD4 T cell responses: However its impact on CD8 T cells is much less clear. Building on published and preliminary data, we propose that IL-4 plays a critical and unexpected role in supporting the CD8 T cell response to pathogens. These findings will be investigated further to define the exact role of IL-4 responsiveness in the CD8 T cell response, and additional work will test the novel concept that IL-4 cytokine therapy could be used to enhance CD8 T cell protective immunity against malarial parasites.